This invention relates to gauges and, more particularly, to a gauge for determining the squareness of the edge of an ice skate blade.
An ice skate blade is sharpened by a grinding wheel on an axis of rotation parallel to the longitudinal direction of the ice skate blade. Consequently, the blade edge takes the form of a shallow, concave surface. The blade has two, parallel, planar sides terminating in narrow parallel ridges, the peaks of which define the opposite sides of the concave edge. The blade edge should be square with the sides of the blade. That is, any imaginary transverse line extending through, and in mutually perpendicular relationship with the peaks of the ridges, should also be perpendicular to the sides of the blade.
Unfortunately, with time and use, the blades lose their squareness. A minor deviation from squareness will neither be perceived by, nor have a significant effect on the performance of, a novice skater. However, surprisingly, a minor deviation from squareness in a skate blade, even a deviation so slight as not to be detectable visually, will impair the performance of an advanced skater.
To compensate for the deviation from squareness in his or her skate blade, the advanced skater is forced to lean to one side or the other. Excessive leaning and overcompensation significantly reduces mobility and increases the chance of falling. Ice skate blades should therefore be checked frequently to optimize performance and avoid the hazard of falling. An out of squareness condition at the edge of a blade also provides an indirect indication that the skate requires sharpening.
Various devices have been proposed to check the squareness of the edge of an ice skate blade. One such device, described in U.S. Pat. No. 5,345,688 to Allen, has a body, an arm pivotally attached to the body and a dial indicator mounted to the arm. Allen also describes a two-piece measuring device having a squaring frame which can be clamped to the skate blade, and a separate element which can be held to the blade by a magnet. The squareness of the blade edge is determined by reading the relationship of edges of the separate element against markings on the squaring frame.
Unfortunately, conventional blade squareness indicators are used primarily by professional sharpeners, and tend to be unwieldy, complex and expensive. Bringing one""s ice skates to a professional sharpener for squareness checks is time consuming and impractical. Therefore, it is desirable to provide a device for checking the squareness of a blade which can be used easily and readily by the skaters themselves to check the squareness of their skate blades and to determine whether or not sharpening is needed.
It is also desirable to provide a simple, portable blade squareness indicator which is accurate and precise.
A gauge having a pivoted pointer with a blade edge-engaging surface would be an ideal blade squareness indicating device. However, no such device has achieved widespread use. The reason that no pivoted pointer gauge has achieved success may be related to the large amplification of movement needed to measure very small deviations from squareness. Even if care is taken to clamp an indicator having a pivoted pointer onto a skate blade, it is difficult to maintain a tight relationship between the blade edge and the blade edge-engaging surface of the pointer. Unless a tight relationship is maintained, the pointer will be able to rotate back and forth about its pivot. The indicating end of the pointer, being remote from the pivot, will be able to move through a considerable distance. The result would be an unacceptable ambiguity in the indication of blade squareness.
It is an object of this invention to provide an ice skate blade gauge, for use by a skater, which is inexpensive, simple in design, easily made and easy to use, and which provides a high degree of precision and accuracy in measurement of the squareness of the edge of an ice skate blade.
The gauge in accordance with the invention comprises a clamp, which is removably connectible in a fixed relationship with an ice skate blade, and an arm pivoted on the clamp for rotation about a pivot axis to which the arm extends transversely. The arm has a blade edge-engaging surface which is adjacent to the pivot axis. An indicator, remote from the pivot axis, cooperates with the arm to display the rotational position of the arm relative to the clamp.
The arm is pivoted on the clamp by a resilient pivot defining the location of the pivot axis. When the clamp is connected with the blade, the blade may press against the blade edge-engaging surface of the arm and urge the arm in a direction to exert a force on the pivot and move the pivot axis laterally. A reaction force exerted by the pivot as a result of the resilience of the pivot ensures firm contact between the blade edge and the blade edge-engaging surface of the arm.
A preferred gauge in accordance with the invention comprises a body having a recess extending from a first face of the body to a location within the interior of the body and extending from a second face on one side of the body to a third face on a side of the body opposite said one side. This construction provides a substantially U-shaped recess adapted to receive an ice skate blade. The recess has a side wall and a clamping means opposite the side wall of the recess, the clamping means extending into the recess for contacting a side of the ice skate blade and securing the ice skate blade against the side wall of the recess. An indicator arm is provided in contiguous, face-to-face relation to the second face of the body and extends in a direction parallel to the second face. The arm has a base engageable with the edge of an ice skate blade when the blade is received in the recess. The second face of the body and the indicator arm have cooperating markings and a pointer for indicating the squareness of the skate blade edge. A hole in the second face receives a spring pin. The hole extends from the second face into the body in a direction perpendicular to the second face, and has a bottom. The spring pin extends through the hole and pivotally attaches the indicator arm in contiguous relation to the second face of the body. The spring pin is connected to the body at the bottom of the hole and to the indicator arm outside the hole. A clearance is provided between the pin and the hole so that the pin can flex laterally, ensuring firm contact of the base of the indicator arm against the skate blade edge when the clamping means secures the body in a fixed relationship with the ice skate blade in the recess.
Preferably, the clamping means comprises a threaded fastener extending through a threaded hole in the body into the recess. Tightening of the fastener forces the skate blade against the side wall of the recess.
As following description will explain in detail, in the operation of the gauge, the blade-engaging surface of the pivoted indicator arm is held tightly against the blade edge by the resilience of the pivot pin, eliminating backlash in the movement of the pointer and ensuring a precise and accurate indication of squareness, or deviation from squareness in the ice skate blade.
Other objects, details and advantages of the invention will be apparent from the following detailed description, when read in conjunction with the drawings.